短季棉中棉16高产稳产生化机理的研究

 对中棉16（G. hirsutum）等5个短季棉品种大田栽培条件下第十叶片及盆栽子叶附体或离体状态下某些生化变化作了研究。结果表明：中棉16及姊妹系中427体内超氧物歧化酶（SOD），过氧化物酶（POD）和过氧化氢酶（CAT）活性强，能及时清除体内有害自由基，使细胞器、核酸、蛋白质等免受伤害、保持活性。因而叶绿素和可溶性蛋白质降解慢，幅度小，能有效进行光合作用，形成更多光合产物，使该品种高产优质。中棉10的SOD、POD、CAT活性小，不能及时清除体内有害自由基的危害，致使棉株过早衰老，丧失光合能力，造成低产。辽棉7号的SOD、POD、CAT活性居中，但离体子叶后期高于其它品种，叶绿素降解速度居中，田间附体叶片蛋白质降解较慢，离体子叶则降解快。由于该品种清除酶类在棉株生长前期活性强，后期稳定，同时该品种植株高大，生长势强，可能为晚熟原因之一。

RESEARCHES ON THE BIOCHEMICAL MECHANISM OF HIGH CONSISTENT YIELD OF SHORT SEASON COTTON ZHONGMIANSUO 16

Research was conducted on some biochemical changes of the 10th leaf of 5 short season cottons including Zhongmiansuo 16 (Gossypium hirsutum)in field and the intact and in vitro leaves of the same cottons grown in pots. Research results show that the SOD, POD and CAT in leaves of Zhongmiansuo 16 and the sibling Zhong 427 have high activities, which can timely get rid of the harmful free radicals in leaves, and can protect organelles, nuclear acids and protein from damage so that they can maintain activities. These lead to slow degradation of chlorophyll and soluble protein within a narrow range, and to effective photosynthesis of leaves, so that the plant produces more photosynthetic assimilates, resulting in high yield and better quality of cotton. The SOD, POD and CAT in Zhongmainsuo 10 have low activities and cannot get rid of the free radicals in leaves. Consequently the cotton plants degenerate prematurely, lose capability of photosynthesis, and give a low yield. The SOD, POD and CAT in Laiomain 7 have medium activities, but those in in vitro leaves are higher than those of other varieties in late season. The degradation rate of its chlorophyll is intermediate. The protein in intact leaves of plants in field degradates slowly, and that in in vitro leaves degradates quickly. This variety being able to get rid of enzymes has a high activity in early growth stages, and has stable activities in late season. Its tall plant and high growth vigor may be one of the causes of late maturity.